Pressure actuated release mechanism

Abstract

A pressure-actuated release mechanism is assembled using a prebuckled pipe segment as a pressure-triggering mechanism. The trigger mechanism is employed to attach buoys to an offshore structure or pipeline under construction. The attached buoys move with the structure or newly added pipe string toward the sea bottom, easing the descent. As a preselected external pressure is sensed, the buckle in the pipe segment propagates and the trigger mechanism actuates, releasing buoys from the structure or pipeline as each buoy in turn reaches the same depth or pressure.

What is claimed is: 
     
       1. Apparatus for use in deploying a structure below the surface of water by a controlled descent comprising: flotation means;   fastening means for releasably securing said flotation means to the structure; and   actuating means partially buckled at a preselected pressure and susceptible to further buckling only after the preselected pressure has been reached at a critical water depth, said further buckling being operative to release said fastening means.   
     
     
       2. The apparatus of claim 1 wherein said actuating means is a partially flattened container and said further buckling occurs via a propagating buckle mechanism. 
     
     
       3. The apparatus of claim 2 wherein the container is a cylinder with capped ends. 
     
     
       4. The apparatus of claim 2 wherein the fastening means is a lever attached to the actuating means and manipulative by buckling of the actuating means. 
     
     
       5. The apparatus of claim 4 wherein the flotation means is secured to the opposite end of the lever and is releasable by manipulation of the lever caused by buckling of the actuating means. 
     
     
       6. The apparatus of claim 1 wherein the structure is a pipeline, the flotation means is a series of buoys attached to the fastening means and is operative to release each buoy after the actuating means associated with each fastening means has reached a preselected depth.